Multiple head tube bending device



J. STlRLING MULTIPLE HEAD TUBE BENDING DEVICE Oct. 11, 1960 2 Sheets-Sheet 1 Filed June 20, 1958 FIGJ INVENTOR.

James Stirling AT w RNEY Oct. 11, 1960 J. STIRLING 2,955,495

MULTIPLE HEAD TUBE BENDING DEVICE Filed June 20, 1958 2 Sheets-Sheet 2 INVENTOR. James Stirling 'ATT EY United States Patent James Stirling, 109-26 209th St., 4 Queens Village 2V9,N.Y.

Filed June 20,195 ser. No. 743,452

2 Claims. c s1-,-1s

This invention relates to tools and more particularly to a hand-operated tool which may be used for bending tubes.

Tube benders of the portable hand-operated type have been perfected with means for making a single bend in a tube, but have no satisfactory or convenient means for making complex bends without utilizing other associated or auxiliary tools.

It is' the object of the present invention to provide a'novel tube bending-device having means to facilitate fabrication of multiple bends in a tube.

A further object of the invention is to provide a portable tube bending device with a multiplicity of forming heads positionably related to each other for fabricating vtubing having complex bends.

-A further'object is to provide a hand-operated tool having at least two forming heads angularly positionable relative to one another for making bends in a tube in the same plane or in dissimilar planes.

A further object is to provide a multiple forming head hand-operated tube bending device with angular and linear graduations to indicate the relative angular displacement of and distance between bends formed in a tube.

The present invention comprises a hand-operated tool for bending tubes with complex configurations. The tool includes a first forming head movable relatively to a second forming head, and with said heads being angularly positonable relative to one another. Means are provided to show graduations for linear positioning of the forming'heads to preset the tool for a predetermined distance between bends, and also to indicate the relative angular displacement of the heads in order to establish the relative planes of the bends to be formed.

While certain objects of the invention have been set forth herein, it is to be understood that other objects nd advantages may be apparent from a perusal of the %isclosure herein. It is to be understood that the present s rowing is by way of illustration only, and various changes a d modifications may be made by me in the invention wfithout departing from the spirit thereof.

, {In the drawings:

' Fig. 1 is a side view of one-form of the invention.

ig. 2 is a partial side view of a modification of the in ention shown in Fig. 1.

Fig. 3 is an end view of the device shown in Fig. 2 with the\ first and second forming heads aligned and shown in solid lines, and with other views shown in dotted lines of one head being angularly displaced relative to the other.

Fig. 4 is the partial top view of the invention shown in Fig. 2 with the swivel arm also shown in a dotted position and being angularly displaced 90 from another forming head.

Fig. 5 is a side view of a modification of the work clamp for the second forming head.

Fig. 6 is an end view of the device shown in Fig. 5.

Fig. 7 is a further modification of the work clamp for gene of the forming heads.

. 2 Fig. *8 is an end view of the work clamp shown in Fig. 7. I

Referring to the drawings: the hand-operated-tube bending device, designated generally by the reference numeral has a handle 21 secured to a first forming head 22 by any convenient means such as being threadedly connected. A flat portion 23 is formed lengthwise on the upper edge of the handle to provide a surface for indicating graduations of linear measurement for setting one forming head a predetermined distance from the other forming head to establish the linear distance of the tube portion between adjacent bends.

The first forming head'22 is shaped with a circular groove 24, formed in the edge thereof, for a distance which in the present instance is greater than 180. The

groove is substantially semi-circular in cross section and of a dimension for a particular size tube.

A bending arm 26 is pivotally mounted by pin 28 to the forming head link 30, with the opposite end of the link being pivotally mounted at the center of the forming head 22 by the forming head stud 32.

A shoulder 34 is formed by one part of a notch ma chined into the first forming head 22.

A work clamp 36 is formed in any convenient manner to swing about the axis of handle 21, with a finger portion 38 of the clamp movable to engage and hold the tube in a predetermined position relative to the circular groove 24. In operation, after the tube has been placed under the work clamp 36 and into the leading edge of groove 24, the bending arm 26, which initially is at the top of the first forming head, is rotated so that shoe 40, having a linear groove of semi-circular contour, engages the tube. As the bending arm 26 is moved downwardly while the tool handle and the tube remain stationary, the shoe'groove 42 engages the tube so that the tube may' be bent in the circular groove 24 for any particular angular curvature as represented by the angular graduations on the flat surface of the forming head 22.

After the first bend in'the tube has been made, the second bend may be made by utilizing the second forming head movably connected with the handle of the tool.

A bifurcated slidable bracket 45 carries a bracket clamping'screw which rides in a spline 46 formed axially in the handle 21 on the side opposite the flat portion 22. The bracket clamping screw 47, having a knurled head, is threadedly connected with said bracket and engageable with the handle via the spline to adjustably position the bracket axially along the handle so that the bracket surface 49 may be positioned relative to the linear graduation 50. This positioning of the bracket establishes the second forming head 51 relative to the first forming head by the desired amount. The swivel arm 52 is L-shaped and has a hub portion 53 which fits into the space formed by the spaced fingers of the bifurcated bracket. A wing nut stud 55 pivotally secures the bracket to the swivel arm 52, and a wing nut 57 is threadedly connected to the stud which mayberotatable or pinned to the bracket. Angular graduations 58 are shown on a curved surface of the bracket so that when the limit means 59 formed as a shoulder on the hub portion 53 engages the bottom of the slot, the swivel arm 52 will position the plane of the second forming head '51 in alignment with the plane of the first forming head 22, and the index 60 will be aligned with the angular indication of zero (*0) degrees thereby indicating that a reverse curve will be formed in the tubing and with both curves being formed in the identical plane as when the device is aligned as shown in Fig. 1.

The second forming head 51 has a groove 62 formed therein, which groove like the groove 24 in the first forming head is substantially semi-circular in a horizontal cross section, with said groove being arcuate and of the same contour and radius as that of the arcuate or curved groove 24 provided in the first forming head.

A work clamp 64 is pivotally mounted on swivel arm 52 and has a groove 65 complemental to the groove 62 formed in thesecond forming head. I

' In operation, in order to form opposite bends in a tubing, swivel arm 52 is positioned longitudinally on the handle 21, so that the front surface 49 of the bracket is aligned with the desired graduation 50 on the handle, thereby pre-setting the linear distance between the formed radius and the second radius to be formed. By rotating the swivel arm 52 to the proper angular position, by set ting the same to the correct graduation 58, the angular displacement between the plane of the formed bend and the plane of the second bend to be formed is established.

It will be noted that the semi-circular groove 62 in the second forming head and the semi-circular groove of the first forming head would be on opposite sides of a tube to be bent, with a common axis for both heads, when the second forming head is substantially contiguous with the shoulder 34 of the first forming head and with no linear portion between the two curves to be formed in the tube. Consequently, after the first curve has been formed in the conventional manner, the tube is removed and the curve of the tubing is positioned in the groove of the second forming head 51 and held therein by the work clamp, depending on the particular type of work clamp used. When the tubing is thus properly placed and held, the bending arm 26, which is normally in the upper position, is then moved downwardly to form the second bend in the tubing which is aligned with the previously formed bend in the tubing, depending on the linear displacement of the bracket 45 on the handle 20, and the angular displacement of the swivel arm 52 relative to the bracket 45.

In Fig. 2, a modification of the forming head clamp 70 has a groove 71 formed therein, similar to groove 65 of the work clamp 64 shown in Fig. 1. In Fig. 2, the forming head clamp 70 is pivotally secured by pin 72 onto the second forming head '51. The dotted position 73 shows the forming head clamp moved out, preparatory to receiving the tube to be clamped, prior to the bending operation of the second curve in the tube.

Fig. 3 shows the openings 75 and 76 between the respective complemental grooves to receive different por tions of the tube to be bent with the tool portion substantially as positioned in Fig. 2. Dotted positions 78 and 79 represent the swivel arm 51 displaced approximately 45 and 90, respectively, from the solid line position shown in Fig. 2.

Fig. 4 shows the top view of the forming head shoulder 34 relative to one edge of the second forming head 51, wherein there is little or substantially no linear displacement between two curves of the forming heads.

In Figs. 5 and 6, the removable work clamp 80 has a shoulder portion 81 to receive the clamping screw 82 therein, which clamping screw may engage the small recess 83 as a pivot point formed in the second working head. When this work clamp arrangement is used after the first bend has been formed in the tube, the tube bend may be positioned in the second forming head and clamped in place by the work clamp which has a groove with the contour and radius complemental to the groove of the second work clamp.

The dash-dot lines 85 and 86 in Fig. 6 represent the plane of other representative angular positions of the second forming head relative to the first forming head axis with the removable work clamp being used.

Figs. 7 and 8 show further modifications of a work clamp 89 with a boss 90 secured to one surface of the forming head. The work clamp is pivotally mounted on the boss by the pin 91, so that by pressing the projection 92 in the proper direction, the work clamp may be moved toward or away from the groove of the second forming head to permit'a tube to be inserted or removed therefrom.

The second forming head is shown swingable in a certain path relative to the first forming head. However, it is to be understood that the second forming head may be arranged or modified accordingly to swing in any other suitable or desirable position to facilitate fabrication of multiple bends in a tube, pipe or other bendable material.

What is claimed as new and desired to be secured by Letters Patent of the United States is:

1. In a tube-bending device having a handle, a first forming head secured to said handle and having a curved peripheral groove formed therein, a shoe having a groove therein with a transverse cross-section complemental to the transverse cross-section of the groove in said first forming head for forming a first bend in a tube in a predetermined plane, and a second forming head adapted to position and releasably hold said predetermined plane of said tube relative to said first forming head for forming a second bend in said tube in a plane different from the plane of said first bend.

2. In a tube-bending device having a handle, a first forming head secured to said handle and having a curved peripheral groove formed therein, a shoe having a groove therein with a transverse cross-section complemental to the transverse cross-section of the groove in said first forming head for forming a first bend in a tube in a predetermined plane, and a second forming head adapted to position and releasably hold said predetermined plane of said tube relative to said first forming head for forming a second bend in said tube in a plane different from the plane of said first bend, and means for indicating the angular relation of the plane of the first bend to the plane of the second bend.

References Cited in the file of this patent UNITED STATES PATENTS 641,535 McKibben Jan. 16, 1900 983,664 Wilson Feb. 7, 1911 1,264,249 Yoder Apr. 30, 1918 1,889,239 Crowley Nov. 29, 1932/ 2,730,157 Ponting Ian. 10, 5 2,740,309 Martin Apr. 3, 1956 2,796,784 Kowal et a1. June 25, 1957 FOREIGN PATENTS 1,065,945 France Jan. 13, 1954 

